Terminating SWA to existing sockets

[alan0259]

Hi everyone,

I'm looking to put two power sockets in my garden shed. The shed is about 10 meters from the house, about 20-25 meters the way I plan to route the cabling.

I've researched this and have come up with the conclusion show in the pic which I hope is mostly correct.

I plan on using 2.5mm 3 core SWA, connecting this to an existing twin plug socket upstairs (upstairs hardly runs any power).

The shed will be running the occasional plug in light, possibly a small electric heater in winter for a short time.

Hope the picture explains my plans and I hope you guys can help :yes:

Cheers,
Alan

 

[telectrix]

you don't want 2 RCDs. and the problem you'll get is that a fault in the shed will trip the house sockets RCD. if you can live with this OK. better to come from the CU if possible. another concern is that the SWA is protected by a 32A MCB. needs fusing down to 20A or less.

 

[alan0259]

you don't want 2 RCDs. and the problem you'll get is that a fault in the shed will trip the house sockets RCD. if you can live with this OK. better to come from the CU if possible. another concern is that the SWA is protected by a 32A MCB. needs fusing down to 20A or less.

Hi Telectrix, sorry I've confused things.

I thought all the B32 things in my CU were actually RCD's!

What's labelled as "sockets" I have a Hager MT132 B32.

Could I get away with replacing the 32A MCB with a 20A or less? Would the rest of my sockets work ok with this?

Thanks for your help.

 

[monkeyelectric]

Hi Telectrix, sorry I've confused things.

I thought all the B32 things in my CU were actually RCD's!

What's labelled as "sockets" I have a Hager MT132 B32.

Could I get away with replacing the 32A MCB with a 20A or less? Would the rest of my sockets work ok with this?

Thanks for your help.

You may not want to hear this but i don't think you should be doing this work yourself, you should get 2 or 3 quotes from qualified electricians to do the work! You can ask them if you can dig the trench for the swa, that'll save a bit

 

[telectrix]

as the upstairs ring final is generally lightly loaded, then reducing the MCB to 20A should not cause any problems. if there's no RCD on that circuit, then fitting a RCD socket in the shed is advisable. tghen from the RCD socket , fit a 5A FCU to feed the light/s.

 

[G power]

Obvious question - how do you plan on glandung tge SWA into a standard socket ?

- - - Updated - - -

Oops spell check !

 

[G power]

Ah - have just seen pic ! It is Sunday tho!

 

[telectrix]

and be sure to gland the SWA properly.

 

[Octopus]

DIY alert!

 

[brman]

I think monkeyelectric (and Murdoch!) might have a point.A few things to consider before you dive it......

1) If the breaker labelled "sockets" is an MCB it still doesn't mean you don't have an RCD. You might still have a couple of RCDs protecting that circuit so you do need to consider discrimination.
2) I'd be thinking about fusing the spur to the shed rather than change the protective device for the whole circuit. It does depend what you are trying to achieve though
3) have you done any voltage drop calcs?
4) Have you considered extraneous conductive parts in the shed and the impact of your earthing system?

 

[markc123]

I think monkeyelectric (and Murdoch!) might have a point.A few things to consider before you dive it......

1) If the breaker labelled "sockets" is an MCB it still doesn't mean you don't have an RCD. You might still have a couple of RCDs protecting that circuit so you do need to consider discrimination.
2) I'd be thinking about fusing the spur to the shed rather than change the protective device for the whole circuit. It does depend what you are trying to achieve though
3) have you done any voltage drop calcs?
4) Have you considered extraneous conductive parts in the shed and the impact of your earthing system?

My suggestion also.

Saying that though, isit totally impossible to get a sparks in and wire your shed independant from the CU to a small CU in the shed? Got more scope for things in the future then and a better job all round.